Multiply routine for DW=W * W. Smaller than library "al@mul" for PIC18

I have developed a smaller code version of the library multiply routine (al@mul)
- this multiplies WORD * WORD, to produce DWORD (as al@mul)
- uses same library variables (as PDS Beta 3.5.2.2)
- mine uses 120 program bytes, compared to library 184 bytes (both including CALL)

I attach a ZIP with example use of code (using Macro), with the routine in its own BAS include.

Also included is the resultant ASM for "MUL_WW"
- the BAS uses ALIAS so that the library variables can be "shared"
- as these locations will vary in typical application code, ASM version would be used (instead of source BAS)

I hope it is of interest.

I also have a version (MUL_SWW, 200 bytes) which treats the WORDs as signed, producing the expected DWORD result for all sign combinations.

Alan.

Attachment 1165